This invention relates generally to a drive for a feed conveyor, rock trap beater, and header of an agricultural combine, and more particularly, to a drive for transferring rotatable power from a power source located on the main combine chassis to the feed conveyor, rock trap beater, and header, utilizing a series of drive shafts, universal joints, and gear boxes, which provides more efficient power transmission, is less bulky and has improved durability and reliability and requires less maintenance than drives utilizing belts and/or chains.
It is well known to utilize drive shafts, universal joints, and gear boxes in various combinations with drive belts and/or chains, for transferring power from a power source on the main chassis or frame of a combine, such as an internal combustion engine, to a feed conveyor, rock trap beater, and/or header on the forward end of the combine. Reference in this regard, Adams U.S. Pat. No. 3,535,859, issued Oct. 27, 1970 to International Harvester Company which discloses a header construction for a combine having a drive system including a combination of drive shafts, universal joints, and a gear box, which received power from a belt drive. Reference also Rippel U.S. Pat. No. 5,904,032, issued May 18, 1999, which discloses a belt driven header and feed conveyor which receives power through a drive shaft and universal joints.
However, limitations of the above-discussed power transmission arrangements include reduced power transmission efficiency resulting from the use of drive belts and/or chains; complex and bulky safety shielding required for the belts and/or chains, particularly when transmitting power across spaces to powered elements articulatable relative to the main chassis such as a feeder and header. Such shortcomings limit the header drive power potential and serviceability, and increase machine width, each of which can be disadvantageous.
Additionally, the front wheels of a combine are typically positioned beside and outwardly of the rearward end of the feed conveyor and the forward end of the main chassis frame of the combine, and in some instances, it may be desirable for the front wheels to be steerable. As a result, the lateral space between the wheel and the drive arrangement for the feed conveyor and header may additionally reduce the amount of space or clearance for turning the wheels, thereby limiting the steerability of the combine.
Thus, what is sought is a drive for the feed conveyor, header, and optionally a rock trap beater, of an agricultural combine which overcomes many of the shortcomings and limitations discussed above.
According to the present invention, a rotatable drive for a feeder and a header of an agricultural combine for connecting spaced rotatable elements on the feeder and the header to a rotatable power source on a chassis of the combine, which overcomes many of the shortcomings and limitations discussed above, is disclosed. The feeder and the header are jointly mounted to the chassis for pivotal movement relative thereto about a predetermined pivotal axis through a predetermined range of harvesting positions. The present drive includes a first gear box mounted on the feeder for pivotal movement therewith and including a rotatable input, a first rotatable output rotatably connected to the input and to at least one of the rotatable elements, and a second rotatable output rotatably connected to the input. The drive includes a second gear box mounted on the feeder and having a rotatable input rotatably connected by a drive shaft or transfer shaft to the second output of the first gear box and at least one rotatable output connected to another of the rotatable elements. A plurality of drive shafts are rotatably connected in end to end relation one to the other, respectively, between the rotatable input of the first gear box and the rotatable power source on the chassis of the combine, one of the drive shafts being rotatably connected by universal joints on opposite ends thereof to another of the drive shafts and to the input of the first gear box, respectively, and having an axial center portion intersecting or located substantially coincident with the pivotal axis when the feeder and header are within the range of harvesting positions.
According to a preferred aspect of the invention, the rotatable elements on the feeder include a conveyor and an optional rock trap beater. According to an optional preferred aspect of the invention, the output and drive shaft or transfer shaft connecting to the second gear box are offset sidewardly toward the side of the feeder from the input of the first gear box so as to provide a space or clearance for turning of an adjacent steerable wheel of the combine.